A member of a group of gastropod molluscs; most species secrete a spiral shell for protection. Some species of snails don't make shells and are known as slugs. Snail moves slowly, and consequently needs help from others often in order to get around, often by riding on Franklin's shell. Got angry in one episode by Franklin's excessive helping, Snail proved his capability by scaling a tall cliff to gather some crystals for the group. freshwater or marine or terrestrial gastropod mollusk usually having an external enclosing spiral shell escargot: edible terrestrial snail usually served in the shell with a sauce of melted butter and garlic gather snails; "We went snailing in the summer" The name snail applies to most members of the molluscan class Gastropoda that have coiled shells. Other gastropods, which lack a conspicuous shell, are commonly called slugs, and are scattered throughout groups that primarily include snails. Snails are found in freshwater, marine, and terrestrial environments. While most people are familiar with only terrestrial snails, the majority of snails are not terrestrial. ... “snail”在英汉词典中的解释 英音：[sneil]美音：[snel] snail KK: [] DJ: [] n.[C] 1. 蜗牛 2. 动作迟缓的人(或动物) 3. 蜗形轮(=snail wheel) 2、Snail基因 与蜗牛一词毫无关系，只是基因组中的一个基因。 锌指转录因子Snai属于Snail超家族成员，Snail家族成员主要有Snail，E12，E47，ZEB1，SIP和Slug等，其家族成员具有相似的结构，由一个高度保守的羧基末端及一个高度可变的氨基末端构成，其结构上的差异主要表现在中间P-S富集区域.近年一些研究证实，一些恶性肿瘤Snail呈高表达，高表达的恶性肿瘤多分化差、易发生转移和复发及侵袭能力强，认为是一个反映恶性肿瘤预后不良的重要生物学标记物. Snail基因的表达产物是一种在上皮-间充质转分化(epithelial-mesen-chymal transition, EMT)过程中居于重要地位的的转录因子。EMT是包括非小细胞肺癌在内的多种肿瘤细胞获得侵袭转移能力的重要机制。